Ore concentration



Patented Aug. 10, 1926.

JOHN W. LITTLEFOBD, OF ALAMEDA, CALIFORNIA, ASSIGNOB TO MINERALS SEPARA- TION NORTH AMERICAN CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF mums.

ORE CONCENTRATION,

2H0 Drawing.

This invention relates to the froth-flotation concentration of ores and is herein disclosed as involving in suitable admixture, the use of asphalts, asphaltites or pyro- 5 genous asphalts as mineral-frotl'iing agents. I have discovered that certain classes of hydrocarbons used in ccrtaip combinations may be used very cficctive'y as mineralfrothing agents with a great many ores, either with or without mineral-frothing agents of hitherto recognized types. I have found that with man ores substantially the same results are obtained by using. mi'neral-frothing agents, various materials such as the asphaltite gilsonite or the lake asphalts or the pyrogenons asphalts known as air-blown asphalts, when mixed or carried in or dissolved in hydrocarbons of the benzene series, and I generally use what seems to ban concentrated solution of the asphalt. The air-blown asphalt appears to be equally efi'ective whether made from parattinbase hydrocarbons or asphaltic-base hydrocarbons. The carrier for the asphalt as indicated above, is advantageously a hydrocarbon of the benzene series Such as xylol, but a mixture of hydrocarbons of the benzene series when used as :rcarrier seems to broducc a more effective frothing agent than would be supposed from a comparison of the individual hydrocarbons when used separately as such carriers for the asphalt. (lommcl'clul xylol is such a mixture, and coal-tar naphtha largely consists of such a mixture.

In concentrating many ores it is found advantageous to add carbonate of soda or a small amount of pine oil or other mineralil'rothing agents or both substances. Carbonate of sodaalso has the effect of in creasing the dill'erential action in selecting certain normally fioatable minerals over others when used in combinatic'm with b enzcne-scries hydrocarbons carrying the above described asphalt with or without another or other mineralffrothing agents.

It has been found that a frothing agent consisting of asphalt mined with or carried Application filed April 5, 1922. Serial No. 549,878.

in hydrocarbons of the benzene series, floats carbonate of lead in a lead carbonate ore without artificial sulphidizatiomand moreover floats the portion of the carbonate containing the silver in preference to the carbonate' low in silver. A second treatment with the mixture of asphalt and benzene series hydrocarbon after sulphidization or with concomitant sulphidization will then float the remainder of the lead in the treatment of many ores. Moreover, it has been found that frequently treatment; with the benzene-series hydrocarbons alone sutlices for the second treatment when a first froth has been produced by the asphalt mixed with or carried in the hydrocarbons of the benzene series.

It is also possibleto adjust the proportions and procedure so as to separate from a lead-zinc ore or a lead-zinc silver ore. a first concentrate containing the lead, or the lead and the silver, and low in zinc, and a second concentrate high in zinc and relatively low in silver and lead. Such a. sepa' rat-ion can also be effected in the presence of copper. If the ore also contains normally floatable iron, the-relative proportions of the asphalt and benzene-series frothing agent used can often be readily adjusted so as to float first a lead concentrate and then a zinc concentrate, both low in iron and both relatively free from the other metal, frequently obtaining in the single concentrations, concentrates conforming to the severest requirements of the smelters. Sometimes apreagitation with a benzene-series hydrocarbon and asphalt frothing agent is advantageous, more of the frothing agent being added to form a froth after a suitable amount of the preliminary agitation.

The San Francisco Del Oro lead-zinc ore when agitated for ten minutes with the benzene-series hydrocarbon xylol carrying the blown asphaltic-l'iase petroleum asphalt known as petrolastic cement, used at the rate of 0.7 pounds ol mixture 'per ton of ore, yielded a load concentrate. and upon further agitation for liftcen minutes, with crude sol- Mina, Nevada, when agitated for ten mins are utcs with soda at 5 pounds per ton, and 1.2-

pounds per ton of a mixture of paraffinbase petroleum air-blown asphalt carried in I xylol, yielded a silver-lead concentrate A. F0. hen the remaining pulp was 'itated for 17 minutes with copper sulphate, 0.3 pounds r r per ton, American Tar Products Co. water" gas tar, 1.0 pounds per ton, cnesylio acid, 0.3 pounds per ton, and 0.4; pounds per ton of 7 the same asphalt carried in xylol, it yielded a zinc concentrate B. The results are shown in the following table:

' Assays.

Per cent The result I; g r entiler cent 6.34 I 4. a 25. 6

Pc c

table .8 pounds per ton of ore ing Assays.

Recoveries.

a zinc concentrate.

vent naphtha 0 yielded shown in the follow the she cement -base air-blown asis same ed on th on treatment so of petrola parafiin he Consolidated of Trail, British from t er cent recovery.

Ilemls c"an. Cone. A. Gone. B. Tails...

a Similar results were obta ore by other froth-flotati same except for the 11 instead of the phalt.

Lead-zinc-iron ore Mining and Smelt-lug Co.

itation e perrying .a

0' g: phlde, 2.0 of th yielded poor in silver. following table Recovery per ton, and ton, yielded a d ca A second a tes with sodium sul petrolastic. cement.

s per 5 poun ylol mixture .60 concentrate rich 1n pounds per ton in xylol, 2.3 pounds sodium silicate, 1.5 pound 5 concentrate rich in silver an inn per ton, and 0.

lead and n in the Assays carrie rge amount of lead soda 5.0

la for 12 In pounds trolastie-eement-x The results are show S HCCT we h '9 7m m0 b m 1 C h mu rW 11 em on m m moo .1 5 f d .na w ht a Auw g a 0 2 w .m 1 1 ea S r\ i d mwh A e0 -1n t u e W d Cg c P rfl m m ne mb w w t a u l n m dt w l d ru .l a t nwf a ome m mem nt s P. m 1e 5 P m o c s m 0 W2 twc its 1.1 m nr 0 o aswu nc n r 74 e .l J yW Ln Wn iest on. mspnn hmmmm nud wnt urc un eenfrr nmat g n oou n a n .mns tnfln we d S ln flbo n ms em am n \L m e P m i a 9nm. N l w nu n m q d B 5.1 80 2 na ed t H .11 1 0 anmmflmm eh onn acmem ewm CHCflfiOPGfiTHPt 0640 l m mfi l .OW.1 w uu T 1C v T 1 -116D o 7 m am v Mowu m cw H n at... nem mmw I r m mo m p c PE ED V S d .U mn fl a n Lb .P l a O l n e d.lm mfl. qa.l ll twm l ulb a o dns h G Dog a 0. lik m u a e pSt n ionn m monm wmm r mwt r m c n ma mu dd n b 00 0 .lnt d m v oamnti e nm u l igeo h adaPPiPW 0 5 4 4 concen- B and mident into the tailn in the follow- Per cent recovery te. This zinc is agitated for 7 minutes with 0.3 per ton of Barrett #4 coal tar cree concentrate 7;; of the iron W csults are shou Assays produc 70 duce a zinc concentra trate w pounds osotO t0 (Hint B.

ings.

inn table 'lCll agig. and thee concentrated. 'n in the follow me petro- The reing table:

Recoveries prod a1 Assays pounds per ton of the sa 50 lastic cement to in lead. The fin tation was collected tailings were tab] sults are she Substantially the same results were obtained by similar treatment with a xylol mixture in which petrolastic cement was substituted for. the gilsonite. and 1.3 pounds per ton of such mixture used instead of adding the white pine oil for retreating the lead concentrate.

Aniron hearing lead-zinc ore from the Moulton Mining Co. of Butte, Montana, was agitated 10 minutes pounds per ton, and 0.7 pounds per ton of petrolastic cement carried in xylol toproduce a lead concentrate. This concentrate was. agitated 5 minutes with soda ash, 2.0 pounds per ton, and 0.3 pounds per ton petrolastic cement carried in xylol, to pro duce a finished concentrate and a lead middling. The reject of the first concentrate was agitated 20 minutes with heavy coal tar naphtha 1.0 pounds per ton, to produce a zinc concentrate. This concentrate was reagitated 5 minutes with 0.3 pounds per ton of heavy coal-tar naphtha to produ e a tinished zinc concentrate and a zinc middling. 40% of the iron went into the tailings but only 2% of the zinc and substantially none of the lead. The results are shown in the following table:

Assa 11s.

1 i l Wt Ag Cu. K Pb. Zn Fe Ins.

I I Per Par Per Per Per I cent cent cent 11. 6 7. 4 52. 0 11. 2 9. 7 J 1. 4 l4. 5 19. 0 l 42. 4 10. 2 1. 4 13. 2 16.0 l 0. 4 4. a 1

Ag. Pb. Zn i re Heads 100. 0 100. 0 100. 0 100. 0 30. 0 56. 0 6. 5 8. 8 14. 4 16. 7 2. 7 9. 7 31. 2 25. 0 32. 5 30. 9 8. 2 2. 3 6. 3 10. 5 16. 2 2. O 40. 1

Similar results were obtained when an air-blown paraffin-base asphalt was substituted for the petrolastic cement in the xylol mixture.

An iron bearing gold-silver-lead ore from Redding, California. was given 25 minutes preagitation with sodium silicate 0.8 pounds per ton. a mixture of paraffin-base-petroleum-air-blown asphalt and xylol, 1.0 pounds per ton, and was then agitated 10 minutes with separation of a froth. This concentrate was then agitated for 15 minutes with 1.0 pound of heavy coal tar naphtha per ton of original ore to form a finished concentrate and a middling. Over 90% of the silver and lead were recovered and nearly 80% of the gold, while over of the iron with soda ash, 5.0-

was rejected. The results are shown in the following table:

Assays.

, Wt. Au Ag (11 i Pb Zn Fe. LMW i i l Per cent 0:. Pzrcencler centlercmtPercrnl Heads": 100.0 0.0711 37.9 0.45 2. 1.92 1 2.38 (Jones as 0. 0:; 551.0 nest 30.4 22.0 0.1 Minds, 4 r. 0.0 1 20.6 0.22} 1.02 4.8 i 5.11 Tai|s 2111.0 0.01.", 1,145. 0.08: 0.10 0.3 1.0

Per cent recovery.

Au. Ag. Cu. Pb Zn. Fe

100.0 100.0 100.0 100.0 100.0 100.0 78. 0 114. 5 B2. 3 90. 4. 74. 5 1s. 5 4.0 2.4 2.2 3.2 11.5 10.6 17. 1 a. 1 15. 5 o. 4 15. 0 71.0

aerating a pulp of suitably ground material with a non-acid mineral-frothing agent c0nsisting of mixed benzene-series hydrocarbons and asphalt, and separatin the froth.

2. The process of frothotation concentration which consists in agitating and aerating a pulp of suitably ground material with a non-acid mineral-frothing agent consisting of mixed benzene-series hydrocarbons and asphalt, separating the froth, agitating the remainder of the pulp with a further quantity of mixed benzene-series hydrocarbons, and separating a second froth.

3. The process of froth-flotation concentration which consists in agitating and aerating a pulp of suitably ground material with a non-acid mineral-frothing agent consisting of mixed benzene-series hydrocarbons and asphalt, separating the froth, agitating the remainder of the pulp with a further quantity of mixed benzene-series hydrocarbons and asphalt, and separating'a second froth.

t. The process of froth-flotation concentration of an iron-bearing lead-zinc ore which consists in agitating and aerating a pulp of the suitably ground ore with a nonacid mineral-frothing agent consisting of mixed benzene-series hydrocarbons and asphalt, separating a froth relatively rich in lead, agitating the remainder of the pulp, with a further quantity of mixed benzeneseries hydrocarbons, and separating a second froth, relatively rich in Zinc.

phalt, separating a, froth relatively rich in lead, agitating the remainder of the pulp with a further quantity of mixed benzeneseries hydrocarbons and asphalt, and, sepa rating a second froth relatively rich in zinc.

6. The process of'froth-fiotation concentration which consists in agimting and aerating a pulp of suitably round material with a non-acid mineral-fret ling agent consisting of xylol carrying asphalt, omi sepamining the froth.

momma 7. The process of frothfiotation concentration which consists in agitating .and aerating a pulp of suitably ground material with & nomacid mineruI-fi'othing agent consisting of mixed benzene-series hydrocarbons carrying pamfiinwbaswpot'i-oleurn-air-blown asphalt, and separating the froth.

In testimony whereof, I have affixed my signature to this s 'iocificacion.

JUHN V 7 LITYLEFQRD. 

